A cross fin tube-type heat exchanger used in an air conditioner, a refrigerator, or the like undergoes a process for processing fins that form slits between rows of collars through which a heat transfer pipe is extended. The processed inter-row slits mainly include a cutting slit that completely cuts a portion between rows when forming a predetermined number of rows of fins and a perforated slit that forms non-continuous slits at constant intervals to reduce the transfer of heat between the rows. In the perforated slit, the length of a portion between slits (that is, non-cut portion, hereinafter referred to as the “perforated portion”) and the length of a slit are set to various values in accordance with the specification of the heat exchanger such as the dimensions and shape, the application of the heat exchanger, and the required fin strength. It is thus desired that the fin manufacturing apparatus that forms perforated slits be able to change the lengths of the perforated portion and the slit (that is, non-cut portion and cut portion) in the formed perforated slit.
Japanese Laid-Open Patent Publication No. 10-160378 describes such a fin manufacturing apparatus. A processing device that forms inter-row perforated slits used for the fin manufacturing apparatus of Japanese Laid-Open Patent Publication No. 10-160378 changes a forward-feed pitch of a thin metal plate, which is the material of a fin, to change the lengths of a perforated portion and a slit using the same cutting blades.